Has there been any progress made on new genital herpes medicines? Are they any closer to a cure?

Dawn

Herpes infections are very difficult to treat because the herpes virus "hides out" in nerve cells, where medications do not penetrate well. Unfortunately, there currently is no cure for herpes, and in many patients, the virus periodically reactivates, causing recurrent oral or genital lesions. During the initial outbreak or a recurrence, the virus is in the saliva (in people with oral lesions) or genital secretions (in people with genital lesions), where it is accessible to antiviral drugs. One such drug, acyclovir (Zovirax), can shorten an initial or recurrent outbreak. Continuous, low doses of acyclovir also can markedly reduce the number of recurrences. Two newer medications, famciclovir (Famvir) and valacyclovir (Valtrex) act on the herpes virus in much the same way. These drugs are somewhat more convenient to take and may be more effective in some circumstances.

Recently, there have been a few minor advances in therapy, mainly in treating infections where the virus has become resistant to acyclovir, famciclovir and valacyclovir. However, since resistance to these drugs is quite uncommon, the newer therapies are not of value to the average patient.

Few viral infections can be cured. Although we do not often die of viral infections, recovery is largely because we usually eradicate the virus on our own. We have made almost no progress toward curing chronic (persistent) viral infections, such as HIV (the virus that causes AIDS) and herpes. A few patients are cured of hepatitis B or C infection with antiviral therapy, but these individuals are the exception. The only legitimate hope for curing herpes is a vaccine. Several vaccines have been studied for herpes, and others are in development.

While most people think of vaccines as tools for disease prevention, scientists are developing vaccines that are also expected be used to treat an infection. These experimental vaccines involve injecting a protein (usually part of the virus itself) into the patient, causing an immune reaction that may aid in the body's ability to fight the infection. Two such anti-herpes vaccines have been studied in more than 2,000 people. Unfortunately, these experimental vaccines had only a very small benefit in preventing infection in uninfected study participants and had no effect on the number of recurrences in those who were already infected. According to a report published in March 2000, researchers found that a new vaccine did show an impressive ability to prevent the development of herpes in an animal model. However, while this vaccine shows promise, as scientists know all too well, an experimental drug or vaccine that shows efficacy in animal studies will not necessarily have the same effect in humans.

Novel approaches to vaccination also are being evaluated in early trials. One promising vaccine involves the use of DNA that corresponds to fragments of a virus's genes. In this approach, the DNA is injected into the person being vaccinated and taken up by certain cells of the body. These cells then use the DNA as a recipe for making pieces of viral protein which are "presented" in a way that, in theory, is ideal for stimulating the immune system to make effective antibodies against the virus. Many experts believe that in the years to come, this approach -- which is being studied for a variety of infections, including HIV -- will be the prove to be most successful way of making vaccines.